The invention relates to a motor vehicle door, comprising a door leaf with a drive and a magnetic device as a component of the drive and at least one sensor which is associated with the door leaf.
A motor vehicle door of the above design is, for instance, disclosed in DE 10 2007 026 796 A1, containing a device for securing open doors, tailgates or similar of a motor vehicle. The arrangement provides a stopping and retaining device containing friction surfaces moving in relation to each other. The friction surfaces contain friction bodies made of magnetisable material. Using a closed magnetic flux, the friction surfaces can be held in an applied force position by a friction body. The magnetisable flux is produced by an energisable coil, generating a magnetic field. In addition, a sensor is provided for detecting the opening position of the associated door.
In the known teaching, the material of the friction body has a reversible ferromagnetic property. As a result, the magnetic flux still remains once the magnetic field generated by the coil is switched off but can be cancelled out by applying a magnetic counter field. Such friction bodies with reversible ferromagnetic properties are generally expensive and problematic as regards reliable functioning. Motor vehicles and their associated motor vehicle doors are used in all climatic zones of the world and must thus be able to cope with temperature ranges of between −40° C. to 70° C. without any problem. Due to the Curie effect, it is doubtful whether friction bodies with reversible ferromagnetic properties and using reversibility will be able to cope with such a temperature range. The Curie temperature for ferrites is actually around 100° C. or higher, depending on the material composition, so that a temperature-related impairment of the generated magnetic field can be expected.
A drive for a door leaf as disclosed in US 2006/0156630 A1 contains a planetary gear equipped with an electromagnetic brake. This electromagnetic brake can be used to stop the drive movement of the door leaf where required.
The prior art also contains a door stay as disclosed in utility patent DE 20 2008 011 513 U1. In this door stay, the flow of force applied in the locking operation passes over a release mechanism, containing a separable connection and, in particular, a magnetic connection. This magnetic connection is, amongst other things, based on the magnetic attraction between a permanent magnet arrangement and a seat assigned to the permanent magnet arrangement.
The also relevant EP 1 249 637 B1 discloses a device for damping or suppressing vibrations in a moved system, in particular, in a vehicle drive aggregate. For this purpose, a chamber filled with a magnetorheological fluid is provided, in which a magnetic field can be generated. At least a part of the chamber contains several electric conductors, in which a current flow can be generated.
The known state of the art is not satisfactory in all aspects. The achievable damping and drives cannot be adapted to all potential functional states without problem. In practical application the problem often arises that the movement of a door leaf should be or is desired to be dampened depending on the situation. Prior art embodiments have so far not provided any convincing solutions for this.